Mournblade -
MoK eventually evolved into a group called 'TAG" or Total Aggression Gaming. They had branched out to other games and got tired of trying to find a name that would match the acronym 'MoK'. They may still have their TAG website up if you search for that name.
As an SFC fleet however they are basically defunct, as are the other fleets you mentioned.
SL did indeed crash and burn - it was quite an epic drama, kinda like the diaspora. Several different leagues sprung up in the aftermath - AFCUB became GamerZ (GZ), and their was a league called Gate Runner (GR) and there is also a TIGC, but I think they only do a campaign for SFC. In any case, it was quite chaotic.
In the end, if you go on Gamespy (were you around for Gamespy replacing MPlayer?), you'll find the majority of the players in there are playing for the GZ ladder, otherwise they're in there for fun game. GZ's pretty much got the SFC ladder market.
I would also add that GZ is a much better run league than SL, add much of the pain of match negotiations has been aleviated. You can still run into jerks, but unlike SL, you can just walk away from the table.
Jedi on occasion can be found in the GZ forum, but has largely stopped playing SFC.
Seki is still around from time to time.
If you are at all intersted in checking out GZ:
www.gzleagues.comwww.gzleagues.com/forum